JP2016015622A - On-vehicle communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle communication system that can perform communication among plural ECUs connected to a communication line even when the communication line is broken.SOLUTION: An on-vehicle communication system (1) for performing communication among plural ECUs (5) mounted on a vehicle has a communication device (2), and a communication line (3) which is connected to the communication device (2) at both the ends of the communication line (3) and connected to the plural ECUs (5). The communication device (2) is configured to be capable of transmitting/receiving a signal from one end of the communication line (3), and also transmitting/receiving a signal from the other end of the communication line (3).

Description

  The present invention relates to an in-vehicle communication system that performs data communication between a plurality of ECUs mounted on a vehicle.

  A plurality of ECUs are mounted on the vehicle, and each ECU is configured to control various devices such as an engine, an automatic transmission device, an audio device, a navigation device, and the like. Each ECU is connected to a communication line of an in-vehicle communication system (for example, CAN) in a bus form so that data communication can be performed between the ECUs.

JP 2008-227591 A

  However, in the above configuration, when the communication line is disconnected, communication is performed with respect to the ECU connected to a part of the communication line that is ahead of the disconnection point (that is, a part far from the communication device of the in-vehicle communication system). The problem that can not be executed.

  Accordingly, an object of the present invention is to provide an in-vehicle communication system capable of executing communication between a plurality of ECUs connected to a communication line even when the communication line is disconnected.

  The invention of claim 1 is an in-vehicle communication system that performs communication between a plurality of ECUs mounted on a vehicle, wherein a communication device and both ends are connected to the communication device, and the plurality of ECUs are connected. A communication line, wherein the communication device is configured to transmit and receive signals from one end of the communication line and to transmit and receive signals from the other end of the communication line.

The block diagram of the vehicle-mounted communication system which shows 1st Embodiment of this invention. Flow chart of disconnection detection control Flow chart of disconnection location identification control Flow chart of control when signal is received by first communication unit Flow chart of control when a signal is received by the second communication unit Flow chart of control when a signal is received by the third communication unit Node control flowchart

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 is a block diagram schematically showing the overall configuration of the in-vehicle communication system of the present embodiment. As shown in FIG. 1, the in-vehicle communication system 1 includes a communication device 2, communication lines 3 and 4 derived from the communication device 2, and a plurality of nodes 5 connected to the communication lines 3 and 4. Configured. The node 5 includes a plurality of ECUs (Electronic Control Units) mounted on the vehicle. Moreover, although the vehicle-mounted communication system 1 is comprised by CAN (Controller Area Network), for example, it is comprised by other vehicle-mounted LAN (For example, LIN (Local Interconnect Network), XCP (Universal Calibration Protocol), CANopen etc.). Also good.

  The communication device 2 includes a control unit 6, a first communication unit 7, a second communication unit 8, a third communication unit 9, a disconnection location information transmission unit 10, a confirmation signal storage unit 11, and a node configuration storage unit. 12, a disconnection location information storage unit 13, a communication state storage unit 14, and a disconnection node group storage unit 15. The control unit 6 controls communication, detects a communication state (normal state, disconnection location specifying state, disconnection state), and executes communication with communication control according to the detected communication state. The control part 6 has each function of a disconnection detection means and a disconnection location identification means. The contents of the communication control will be described later with reference to the flowcharts of FIGS.

  The first communication unit 7 communicates with the 0th node 5, the first node 5, the second node 5,..., The Xth node 5 connected to the communication line 3. In a normal state, the second communication unit 8 monitors a signal sent from the first communication unit 7 via the communication line 3 and detects whether or not a communication abnormality (disconnection of the communication line 3) has occurred. Do. The second communication unit 8 communicates with the node 5 connected to the communication line 3 when the communication line 3 is disconnected (specific details will be described later). The third communication unit 9 performs communication with the tenth node 5, the eleventh node 5, the twelfth node 5,..., The first Y node 5 connected to the communication line 4. The third communication unit 9 and the communication line 4 (further, a plurality of nodes 5 connected to the communication line 4) may be configured to be provided in a plurality (two or more).

  The disconnection location information transmitting unit 10 transmits the disconnection location information obtained when the disconnection location of the communication line 3 is specified to, for example, a diagnostic tool outside the communication device 2. The confirmation signal storage unit 11 stores information on a confirmation signal to be transmitted to each node 5 in a state where the disconnection portion of the communication line 3 is specified. In this case, a different confirmation signal is assigned to each node 5 and stored.

  The node configuration storage unit 12 includes each node 5 connected to the communication line 3 between the communication unit 7 and the second communication unit 8, and each node 5 is directed from the first communication unit 7 to the second communication unit 8. The order of arrangement (numbers assigned as 0th, 1st, 2nd,..., Xth in order from the closest to the first communication unit 7) is stored. The disconnection location information storage unit 13 stores information indicating the disconnection location. In this case, the communication line 3 stores information in the form of disconnection between the first node 5 and the second node 5, for example.

  The communication state storage unit 14 stores information indicating which state is the current state among the normal state, the disconnection location specifying state, and the disconnection state. The disconnection node group storage unit 15 sets the group of the node 5 that can communicate with the first communication unit 7 as the group 1 and the group of the node 5 that can communicate with the second communication unit 8 as the group 2 with the disconnection point as a boundary. Store information.

  Each node 5 includes a control unit 16, a node communication unit 17, and a response signal storage unit 18. The control unit 16 controls communication with the communication device 2 or another node 5 via the communication line 3. The control unit 16 transmits a response signal to the communication device 2 when receiving the confirmation signal transmitted from the communication device 2. The node communication unit 17 communicates with the communication device 2 or another node 5. The response signal storage unit 18 stores information indicating the response signal.

  Next, the operation of the above configuration, that is, the contents of control of the communication device 2 (control unit 6) will be described with reference to the flowcharts of FIGS. First, the flowchart of FIG. 2 shows the contents of control for detecting whether or not a disconnection has occurred in a normal state (initial state) in which communication between the first communication unit 7 and each node 5 is normally executed. Indicates.

  In step S <b> 10 of FIG. 2, a disconnection detection signal is transmitted from the first communication unit 7 of the communication device 2 to the communication unit 8 via the communication line 3. Then, it progresses to step S20 and it is judged whether the 2nd communication part 8 received the said signal normally. Here, when the second communication unit 8 normally receives the signal, the process proceeds to “YES”, and the communication control is terminated because the communication line 3 is not disconnected.

  In step S20, when the second communication unit 8 does not normally receive the signal, the process proceeds to “NO”, and the process proceeds to step S30. In step S30, since the communication line 3 is disconnected, the storage content of the communication state storage unit 14 is rewritten to the disconnection location specifying state. And detection control is complete | finished. The detection control (flowchart in FIG. 2) is executed at predetermined time intervals in the normal state.

  Next, when the stored content of the communication state storage unit 14 is in the disconnection location specifying state, the control of the flowchart in FIG. 3, that is, the control for specifying the disconnection location of the communication line 3 is executed. First, in step S100 of FIG. 3, a confirmation signal is transmitted from the first communication unit 7 to the 0th node 5. And the 0th node 5 will transmit a response signal to the 1st communication part 7 of the communication apparatus 2, if the said confirmation signal is received. The control of the 0th node 5 (see FIG. 7) will be described later.

  Then, it progresses to step S102 and the communication apparatus 2 (1st communication part 7) judges whether the response signal from the 0th node 5 was received. If the response signal is not received, the process proceeds to “NO”, proceeds to step S104, and determines that the first communication unit 7 and the 0th node 5 are disconnected.

  On the other hand, if a response signal is received in step S102, the process proceeds to “YES”, and the process proceeds to step S110. In step S <b> 110, a confirmation signal is transmitted from the first communication unit 7 to the nth node 5. In this case, the initial value of n is 0, and confirmation is performed according to the order stored in the node configuration storage unit 12. And the nth node 5 will transmit a response signal to the communication part 7 of the communication apparatus 2, if the said confirmation signal is received. The control of the nth node 5 (see FIG. 7) will be described later.

  Then, it progresses to step S120 and the communication apparatus 2 (1st communication part 7) judges whether the response signal from the nth node 5 was received. If a response signal is received, the process proceeds to “YES”, proceeds to step S130, and n is incremented (+1). Subsequently, it progresses to step S140 and it is judged whether it is n <= X. If n ≦ X, the process proceeds to “YES”, returns to step S110, and repeats the above-described processing.

  If no response signal is received in step S120, the process proceeds to “NO”, and the process proceeds to step S180, where it is determined that the disconnection has occurred between the (n−1) -th node 5 and the n-th node 5. In step S140, when n ≦ X is not satisfied, the process proceeds to “NO”, the process proceeds to step S150, and it is determined that the second communication unit 8 and the X-th node 5 are disconnected.

  Now, after execution of step S150, step S180, and step S104, it progresses to step S160, sets the group of the node 5 which can communicate with the 1st communication part 7 as a boundary from the disconnection location as the group 1, and the 2nd communication part 8 The information of setting the group of the node 5 that can communicate with the group 2 as the group 2 is stored in the disconnection node group storage unit 15. Then, it progresses to step S170 and rewrites the communication state of the communication state memory | storage part 14 to a disconnection state. And this control (flowchart of FIG. 3) is complete | finished.

  Next, the control when the first communication unit 7 receives a signal when the communication line 3 is disconnected will be described with reference to the flowchart of FIG. First, in step S210 of FIG. 4, the first communication unit 7 receives a signal and proceeds to step S220, and determines whether or not the received signal is a signal to be transmitted to the node 5 in the group 2. Here, when the received signal is a signal to be transmitted to the node 5 in the group 2, the process proceeds to “YES”, the process proceeds to step S290, and the signal received by the first communication unit 7 of the communication device 2 is transmitted to the second communication unit. 8 to the node 5 in the group 2 via the communication line 3. And this control (flowchart of FIG. 4) is complete | finished.

  On the other hand, if the received signal is not a signal to be transmitted to the node 5 in the group 2 in step S220, the process proceeds to “NO”, and the process proceeds to step S230. In step S230, it is determined whether the received signal is a signal to be transmitted to the node 5 connected to another communication line 4 (assuming that a plurality of communication units 9 and 4 communication lines 4 are provided, for example). Therefore, the initial value of N is set to 1.

  Then, it progresses to step S240 and it is judged whether a received signal is a signal transmitted to the node 5 of the communication line 4 (N). Here, when the received signal is a signal to be transmitted to the node 5 of the communication line 4 (N), the process proceeds to “YES”, the process proceeds to step S280, and the signal received by the first communication unit 7 of the communication device 2 is 3 Transmit from the communication unit 9 (N) to the node 5 via the communication line 4 (N). And this control (flowchart of FIG. 4) is complete | finished.

  If the received signal is not a signal to be transmitted to the node 5 of the communication line 4 (N) in step S240, the process proceeds to “NO”, proceeds to step S250, and N is counted up. Then, it progresses to step S260 and it is judged whether N <= Z. If N ≦ Z, the process proceeds to “YES”, returns to step S240, and repeats the above-described processing. If N ≦ Z is not satisfied in step S260, the process proceeds to “NO”, and the process proceeds to step S270. In this case, the signal received by the first communication unit 7 of the communication device 2 is transmitted to the node 5 in the group 1. The communication device 2 does nothing. And this control (flowchart of FIG. 4) is complete | finished.

  Next, the control when the second communication unit 8 receives a signal when the communication line 3 is disconnected will be described with reference to the flowchart of FIG. First, in step S310 of FIG. 5, the second communication unit 8 receives a signal and proceeds to step S320, where it is determined whether or not the received signal is a signal to be transmitted to the node 5 in the group 1. Here, when the received signal is a signal to be transmitted to the node 5 in the group 1, the process proceeds to “YES”, the process proceeds to step S390, and the signal received by the second communication unit 8 of the communication device 2 is changed to the first communication unit. 7 to the node 5 in the group 1 via the communication line 3. And this control (flowchart of FIG. 5) is complete | finished.

  On the other hand, when the received signal is not a signal to be transmitted to the node 5 in the group 1 in step S320, the process proceeds to “NO”, and the process proceeds to step S330. In this step S330, whether or not the received signal is a signal to be transmitted to the node 5 connected to another communication line 4 (assuming a plurality of third communication units 9 and four communication lines 4 are provided, for example, Z). In order to determine the initial value of N.

  Then, it progresses to step S340 and it is judged whether a received signal is a signal transmitted to the node 5 of the communication line 4 (N). Here, when the received signal is a signal to be transmitted to the node 5 of the communication line 4 (N), the process proceeds to “YES”, the process proceeds to step S380, and the signal received by the second communication unit 8 of the communication device 2 is 3 Transmit from the communication unit 9 (N) to the node 5 via the communication line 4 (N). And this control (flowchart of FIG. 5) is complete | finished.

  If the received signal is not a signal to be transmitted to the node 5 of the communication line 4 (N) in step S340, the process proceeds to “NO”, proceeds to step S350, and N is counted up. Then, it progresses to step S360 and it is judged whether it is N <= Z. If N ≦ Z, the process proceeds to “YES”, returns to step S340, and repeats the above-described processing. If N ≦ Z is not satisfied in step S360, the process proceeds to “NO”, and the process proceeds to step S370. In this case, the signal received by the second communication unit 8 of the communication device 2 is transmitted to the node 5 in the group 2. The communication device 2 does nothing. And this control (flowchart of FIG. 5) is complete | finished.

  Next, control when the third communication unit 9 (N) receives a signal in the disconnection state of the communication line 3 will be described with reference to the flowchart of FIG. 6 (where N ≧ 1). First, in step S410 of FIG. 6, the third communication unit 9 (N) receives a signal and proceeds to step S420, and determines whether or not the received signal is a signal to be transmitted to the node 5 in the group 1. Here, when the received signal is a signal to be transmitted to the node 5 in the group 1, the process proceeds to “YES”, the process proceeds to step S460, and the signal received by the third communication unit 9 (N) of the communication device 2 is 1 The communication unit 7 transmits to the node 5 in the group 1 through the communication line 3. And this control (flowchart of FIG. 6) is complete | finished.

  On the other hand, when the received signal is not a signal to be transmitted to the node 5 in the group 1 in step S420, the process proceeds to “NO”, and the process proceeds to step S430. In step S430, it is determined whether the received signal is a signal to be transmitted to node 5 in group 2. Here, when the received signal is a signal to be transmitted to the node 5 in the group 2, the process proceeds to “YES”, the process proceeds to step S450, and the signal received by the third communication unit 9 (N) of the communication device 2 is 2 Transmit from the communication unit 8 to the node 5 in the group 2 via the communication line 3. And this control (flowchart of FIG. 6) is complete | finished.

  When the received signal is not a signal to be transmitted to the node 5 in the group 2 in step S430, the process proceeds to “NO” and proceeds to step S440. In this case, the third communication unit 9 (N) of the communication device 2 Since the received signal is a signal transmitted to the node 5 connected to the communication line 4 (N), the communication device 2 behaves as usual. For example, if the signal received by the third communication unit 9 (1) is a signal transmitted to the node 5 connected to the communication line 4 (1), the communication device 2 does nothing. For example, if the signal received by the third communication unit 9 (1) is a signal transmitted to the node 5 connected to the communication line 4 (2), the signal received by the third communication unit 9 (1). Is transmitted from the third communication unit 9 (2) to the node 5 via the communication line 4 (2). And this control (flowchart of FIG. 6) is complete | finished.

  Next, communication control of each node 5 connected to the communication line 3 will be described with reference to the flowchart of FIG. First, in step S510 in FIG. 7, the node 5 receives the confirmation signal (see step S110 in FIG. 3) transmitted from the first communication unit 7. In step S520, the node 5 determines whether the confirmation signal is a confirmation signal addressed to itself. Here, when the confirmation signal is a confirmation signal addressed to itself, the process proceeds to “YES”, the process proceeds to step S530, and the node 5 transmits the response signal to the first communication unit 7 of the communication apparatus 2. And this control (flowchart of FIG. 7) is complete | finished. In step S520, when the confirmation signal is not a confirmation signal addressed to itself, the process proceeds to “NO”, and this control (the flowchart of FIG. 7) is terminated without doing anything.

  According to the present embodiment having the above-described configuration, a plurality of nodes (ECUs) 5 are connected to the communication line 3 whose both ends are connected to the communication device 2, and signals are transmitted and received from one end of the communication line 3 by the communication device 2. In addition, since the signal can be transmitted / received also from the other end of the communication line 3, when the communication line 3 is disconnected, the node 5 on one end side from the disconnection point and the other end side from the disconnection point are provided. The node 5 can communicate via the communication device 2. As a result, even when the communication line 3 is disconnected, communication can be performed between the plurality of nodes 5 connected to the communication line 3.

  In addition, the control unit 6 of the communication device 2 transmits a disconnection detection signal from one end of the communication line 3, and disconnects the communication line 3 depending on whether or not the disconnection detection signal is received at the other end of the communication line 3. Since it comprised so that it might detect, the disconnection of the communication line 3 can be detected correctly and easily.

  Further, when the disconnection of the communication line 3 is detected, the control unit 6 of the communication device 2 starts from the node 5 connected to the plurality of nodes 5 at the part closest to one end or the other end of the communication line 3. Since the configuration is such that the disconnection location of the communication line 3 is specified by performing communication, the disconnection location can be easily specified.

  When there is a first signal to be transmitted to the node 5 (the node 5 in the group 1) connected between one end of the communication line 3 and the disconnection point, the control unit 6 of the communication device 2 Since the first communication unit 7 is configured to transmit the first signal from one end of the communication line 3 (see step S390 in FIG. 5 and step S460 in FIG. 6), the node 5 in the group 2 and the group 1 in the group 1 Communication can be executed between the node 5 or between the node 5 connected to the communication line 4 and the node 5 in the group 1.

  Furthermore, when there is a second signal to be transmitted to the node 5 (the node 5 in the group 2) connected between the other end of the communication line 3 and the disconnection point, the control unit 6 of the communication device 2 Since the second communication unit 8 is configured to transmit the second signal from the other end of the communication line 3 (see step S290 in FIG. 4 and step S450 in FIG. 6), the node 5 in the group 1 and the group 2 Communication can be performed between the nodes 5 in the group 2 or between the nodes 5 connected to the communication line 4 and the nodes 5 in the group 2.

  In each of the above embodiments, the communication device 2 is provided with one communication line 3 that connects both ends. However, the present invention is not limited to this, and the communication device 2 is provided with two or more communication lines that connect both ends. A plurality of nodes 5 may be connected to each of these communication lines.

  In the drawings, 1 is an in-vehicle communication system, 2 is a communication device, 3 is a communication line, 4 is a communication line, 5 is a node, 6 is a control unit (disconnection detection means, disconnection location specifying means), 7 is a first communication unit, Reference numeral 8 denotes a second communication unit, 9 denotes a third communication unit, 16 denotes a control unit, and 17 denotes a node communication unit.

Claims (5)

An in-vehicle communication system (1) for executing communication between a plurality of ECUs (5) mounted on a vehicle,
A communication device (2);
A communication line (3) connected at both ends to the communication device (2) and connected to the plurality of ECUs (5);
The said communication apparatus (2) is a vehicle-mounted communication system comprised so that a signal could be transmitted / received also from the other end of the said communication line (3) while transmitting / receiving a signal from one end of the said communication line (3).   It is provided in the communication device (2), transmits a disconnection detection signal from one end of the communication line (3), and determines whether the disconnection detection signal is received at the other end of the communication line (3). The in-vehicle communication system according to claim 1, further comprising disconnection detecting means (6) for detecting disconnection of the communication line (3).   A part provided in the communication device (2) and closest to one end or the other end of the communication line (3) with respect to the plurality of ECUs (5) when a disconnection of the communication line (3) is detected The vehicle-mounted communication system of Claim 2 provided with the disconnection location specific means (6) which specifies a disconnection location by communicating in order from ECU (5) connected to the.   When there is a first signal that is provided in the communication device (2) and transmitted to the ECU (5) connected between one end of the communication line (3) and the disconnection point, the communication line (3 The vehicle-mounted communication system of Claim 3 provided with the 1st communication part (7) which transmits a said 1st signal from the end of (1). When there is a second signal to be transmitted to the ECU (5) provided in the communication device (2) and connected between the other end of the communication line (3) to the disconnection point, the communication line ( The in-vehicle communication system according to claim 3, further comprising a second communication unit (8) for transmitting the second signal from the other end of 3).

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